using ll = long long;
#define endl '\n'


ll sum1(ll p, ll q) {//O(n)
    ll s = 0;
    for (ll i = p; i <= q; i++) {
        s += i;
    }
    return s;

}

ll sum2(ll p, ll q) {//O(1)
    ll s = (q - p + 1) * (p + q) >> 1;
    return s;

}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);

    long long start = clock();//Mac/Linux  纳秒 vs windows平台下是毫秒
    //被测试程序
    long long end = clock();
    cout << 1.0 * (end - start) / CLOCKS_PER_SEC << endl;
    return 0;
}